Utility poles carried on a pole trailer typically extend 50 feet or more behind a truck of an utility company. Although the truck is highly visible and normally has operating flasher lights when driving, the far ends of the poles represent a safety hazard for the following vehicles.
The image projected by the far end of a pole to a following driver is relatively small as compared to the size of the trailer and of the truck. Therefore, the background view of the truck and trailer to the following driver, can at times cause the illusion that the far end of the pole is further away than it actually is.
Similarly, the driver of the utility truck can misestimate the actual distance of the far end of the pole, especially when the pole is aligned with a line of sight of the driver. These misjudgements often result in backing the pole against nearby structures, fences and other vehicles for examples.
Different types of warning flags have been developed in the past and are still used nowadays for increasing the visibility of the far end of a pole carried on a pole trailer. As a first example, a very popular method for making such warning flag comprises the wrapping a red cloth around a wood stake and nailing the wood stake to the far end of the pole. The red cloth normally lays on the upper surface of the pole or hangs down alongside the pole. In both cases, the flag is hardly visible by the driver of the truck pulling the trailer. Moreover, when the truck is moving at a low speed, or when it is stopped for example, the flag hangs in folds and creases and is hardly visible by the driver of the vehicle following the pole trailer.
A second example of the warning flags of the prior art is illustrated in U.S. Pat. No. 3,678,886 issued on Jul. 25, 1972 to James W. Tibbet. This warning flag is attached to the pole by means of an elastic cord wrapped around the end of the pole. Although this flag always hangs in a fully deployed mode, it normally hangs under the far end of the pole and is not visible by the driver of the truck pulling the trailer.
Yet another example of a tail flag for vehicle is illustrated in Canadian Patent 645,710 issued on Jul. 31, 1962 to Gordon Stanley. This tail flag comprises a C-clamp which is attachable to the load extending behind a vehicle and a U-shaped rod welded to the C-clamp for attaching a red cloth thereto. The flag of this device also hangs down under the load where it is hardly visible to the driver of the vehicle carrying the long objects.